MYOC rs74315328: Understanding This Glaucoma-Associated Variant
The rs74315328 variant is a specific change in the MYOC gene that has been identified in research as a potential factor in the development of primary open-angle glaucoma. This variant is located in a region of the gene critical for proper protein function and is studied for its role in early-onset forms of the condition.
What each genotype means
Typical MYOC profile
This is the most common genotype observed in the general population. It is considered the reference sequence for the MYOC gene at this location.
This is the most common genotype found in the vast majority of individuals across all ancestries.
Increased glaucoma risk
This genotype involves a missense mutation (Tyr437His) in the olfactomedin domain of the myocilin protein. Research has associated this variant with an increased risk for juvenile- and adult-onset primary open-angle glaucoma, though the clinical expression can be variable.
This genotype is rare, with the variant allele occurring at a frequency of approximately 0.0003 in European ancestries.
Elevated glaucoma risk
This homozygous genotype carries two copies of the missense variant associated with primary open-angle glaucoma. Individuals with this genotype may have a higher predisposition to developing glaucoma, and you should discuss your eye health and screening needs with an ophthalmologist.
This genotype is extremely rare in the general population.
What is rs74315328?
The rs74315328 variant is a single nucleotide polymorphism (SNP) located within the MYOC gene on chromosome 1. In genetic terms, this variant represents a specific change in the DNA sequence that can alter the structure of the resulting protein. It is categorized as a missense variant, meaning the change in the DNA code results in a different amino acid being incorporated into the myocilin protein chain. This specific variant is situated within the olfactomedin domain of the protein, a region that is highly sensitive to structural changes. Because this domain is essential for the protein's normal function, researchers focus on this site to understand how genetic variations might contribute to ocular health. It is important to note that while this variant is documented in scientific databases, its presence does not guarantee the development of any condition, as glaucoma is a complex disease influenced by many genetic and environmental factors.
The Role of the MYOC Gene
The MYOC gene provides the instructions for the body to produce a protein called myocilin. This protein is primarily found in the trabecular meshwork, a specialized tissue in the eye that acts like a drain to regulate intraocular pressure by controlling the outflow of aqueous humor. When the MYOC gene functions normally, myocilin helps maintain the structural integrity and proper drainage function of this tissue. Research suggests that certain mutations in this gene can lead to the production of misfolded myocilin protein. This misfolded protein may accumulate within the cells of the trabecular meshwork, potentially causing a toxic gain-of-function effect that impairs the eye's ability to regulate pressure. Elevated intraocular pressure is a primary risk factor for the development of glaucoma, a condition that can damage the optic nerve and lead to vision loss if left unmanaged.
Research and Evidence Strength
The association between MYOC variants and glaucoma has been a subject of study for over two decades. Research has consistently identified rare variants in the olfactomedin domain as significant contributors to juvenile-onset open-angle glaucoma (JOAG) and, to a lesser extent, primary open-angle glaucoma (POAG). The evidence for rs74315328 specifically is considered limited in terms of its overall population impact, though it is recognized in clinical databases as a pathogenic variant in the context of inherited glaucoma. Most studies emphasize that while MYOC mutations are the strongest known genetic link for certain early-onset cases, they account for only a small percentage of total glaucoma cases in the general population. Because glaucoma is multifactorial, the presence of this variant is just one piece of a much larger puzzle. Scientists continue to investigate how these specific genetic changes interact with other biological pathways to influence the risk of developing elevated eye pressure.
Population Frequency
The rs74315328 variant is considered rare in the general population. According to data from the Genome Aggregation Database (gnomAD), the minor allele frequency is approximately 0.0003 in European ancestries. This low frequency indicates that the variant is not common among the general public. Because it is a rare variant, it is not typically found in large-scale screening of the general population and is usually identified through targeted genetic testing in families with a history of early-onset glaucoma. The rarity of this variant underscores that it is not a common cause of glaucoma for the vast majority of people. Genetic frequency can vary significantly between different ethnic and geographic groups, and researchers continue to collect data to better understand the distribution of such variants across diverse global populations.
What You Can Do With This Information
Genetic information regarding variants like rs74315328 is intended for educational and research purposes. If you have received genetic testing results indicating the presence of this variant, it is important to understand that this is not a medical diagnosis. Glaucoma is a complex condition that requires clinical evaluation by an eye care professional, such as an ophthalmologist, who can perform comprehensive exams to measure intraocular pressure and assess the health of the optic nerve. You cannot use this information to predict your health outcomes or to make decisions about medical treatment. If you are concerned about your risk for glaucoma, especially if you have a family history of the disease, the most effective step is to schedule a professional eye examination. Always discuss any genetic findings with a qualified healthcare provider or a genetic counselor who can help interpret the results in the context of your personal and family medical history.
How common is this variant?
The rs74315328 variant is rare, with a minor allele frequency of approximately 0.0003 in European populations according to gnomAD data.
Frequently asked questions
Does having the rs74315328 variant mean I will get glaucoma?
No, having this variant does not mean you will develop glaucoma. Glaucoma is a complex disease influenced by many genetic and environmental factors, and many people with genetic variants never develop the condition.
Should I get tested for MYOC variants?
Genetic testing for MYOC variants is typically only recommended by clinicians for individuals with a strong family history of early-onset glaucoma. You should discuss the necessity of such testing with an ophthalmologist or a genetic counselor.
Is rs74315328 the same as other glaucoma genes?
rs74315328 is a specific variant within the MYOC gene. While MYOC is a well-known gene associated with glaucoma, there are many other genes and factors that contribute to the risk of developing the disease.
What is the difference between juvenile and adult-onset glaucoma?
Juvenile-onset glaucoma typically appears in childhood or early adulthood, while adult-onset glaucoma is more common and usually develops later in life. Both can be influenced by different genetic and environmental factors.
Sources & further reading
Educational information only, last refreshed 9/28/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Encodes the classical Gln368STOP mutation in myocilin, a well-validated genetic cause of juvenile- and adult-onset primary open-angle glaucoma.
Missense mutation in MYOC (p.Gln368Glu) predisposing carriers to elevated intraocular pressure and adult-onset primary open-angle glaucoma.
A pathogenic point mutation in MYOC strongly linked to autosomal dominant primary open-angle glaucoma with high intraocular pressure.
A pathogenic missense variant in myocilin causing trabecular meshwork disruption and juvenile-onset open-angle glaucoma.
Known as the Gln368STOP mutation in MYOC, this nonsense variant is a well-established cause of autosomal dominant juvenile- and adult-onset primary open-angle glaucoma.
A pathogenic missense variant (p.Gln368Ter) in the MYOC gene, a major genetic risk factor for primary open-angle glaucoma.